textproduct: Rapid City

KEY MESSAGES

- Isolated to scattered thunderstorms are expected this afternoon and evening from northeast WY, across the Black Hills, into the northwestern SD. Strong to severe storms could produce damaging winds of 60-75 MPH, hail, and frequent lightning.

- Very warm weather continues throughout the next 7 days.

- Near-critical fire weather concerns continue into early next week, mainly over northeastern WY into southwestern SD.

DISCUSSION

(This Afternoon Through Saturday) Issued at 1152 AM MDT Sun Aug 30 2026

Upper air analysis depicts upper shortwave over northern ID/southern SK. Water vapor imagery shows line of convection developing over central MT/WY and moving eastward. These storms will move into the CWA in the next several hours. Inverted-V soundings indicate damaging wind gusts will be the main concerns with these storms. Some gusts over NW SD could exceed 75+ mph. Right now, there's some uncertainty as to how far south these storms will extend and if they'll impact the Rapid City area.

Broad upper level ridge builds over the central/eastern half of the US for the beginning of the week. This will lead to continuing warm conditions over our CWA and mostly dry conditions, though afternoon storms are possible tomorrow and Tuesday. Deterministic models show the ridge strengthening later in the week, leading to much warmer conditions over western SD and northeastern WY with highs climbing into the mid to upper 90s by Wednesday and Thursday. In addition to the hot temperatures, the very dry airmass will lead to elevated to near-critical fire weather concerns.

AVIATION

(For the 18Z TAFS Through 18Z Monday) Issued At 1130 AM MDT Sun Aug 30 2026

Isolated to scattered thunderstorms are still possible this afternoon and evening from northeast Wyoming, across the Black Hills, into the northwestern South Dakota plains. Thunderstorm initiation is possible as early as 19-20z/1-2pm in central Wyoming. Any storms that are able to get going will track northeast through the area.

Some storms will be capable of producing gusty/erratic winds, localized hail, frequent lightning, and brief vsby drops to MVFR or high-end IFR. Breezy northwest winds are also expected across the region due to a frontal passage. Outside of thunderstorms, VFR conditions will dominate.

FIRE WEATHER

Issued At 1152 AM MDT Sun Aug 30 2026

Isolated high-based thunderstorms are possible across northeastern WY this afternoon and evening. Storms may produce lightning and gusty winds but not much precip. Elevated to near- critical fire weather conditions possible over much of the area tomorrow, especially over northeastern WY where humidities may drop to as low as 10%, however winds are expected to remain light.

Near-critical fire wx conditions are possible later this week in the Wed/Thu timeframe as a hot and dry airmass moves into the region. Afternoon humidities ranging from 10 to 20% and breezy southwest winds will lead to widespread near-critical fire weather concerns across northeastern WY into western SD.

UNR WATCHES/WARNINGS/ADVISORIES

SD...None. WY...None.